GitHub alerts case insensitive (#1389)

* chore: bump markdown-it-github-alerts to 0.3.0 (override markdown-it)

* "revert: bump markdown-it-github-alerts to 0.3.0 (override markdown-it)"

This reverts commit dbc00ee.

* chore: case insensitive gh-alerts

src/markdown-it-plugin-provider.ts

@@ -9,7 +9,7 @@ const katexOptions: KatexOptions = { throwOnError: false };
  */
 export function extendMarkdownIt(md: MarkdownIt): MarkdownIt {
     md.use(require("markdown-it-task-lists"), {enabled: true});
-    md.use(require("markdown-it-github-alerts"))
+    md.use(require("markdown-it-github-alerts"), { matchCaseSensitive: false })
 
     if (configManager.get("math.enabled")) {
         // We need side effects. (#521)